Since so-called multi-contact connectors require a considerable force for their connection, in many cases their manual connection becomes a difficult task. Therefore, lever-type connectors were proposed, in which a pair of connectors can be connected using relatively low force.
As an example of such connectors, a lever-type connector 100, Japanese Patent Application No. 5 (1993)-121121 is shown in FIG. 3. This lever-type connector 100 comprises a plug housing 102, a cap housing 120 and a lever 140 supported by a spring 130. In the side wall 121 of the cap housing 120, there is an opening 122. The lever 140 is designed in such a manner that it can rotate relative to lugs 124 formed in the side walls 121 of the cap housing 120. A flat section 142 of the lever 140 has a notch 146 and a slot 148 connected to it which is inclined relative to the opening 122. On the other hand, on the side walls 103 of the plug housing 102, protrusions 104 are made. When the plug housing 102 is inserted in the cap housing 120, these protrusions 104 slide into the slot 148 of the lever 140, and eventually become engaged with the notch 146. After that, the lever 140 is rotated in the direction of arrow A, resulting in forcing the plug housing 102 into the cap housing 120.
However, in such conventional lever-type connectors, the lever 140 is supported by the spring 130, and in some cases this spring can be distorted out of shape by an external force, resulting in a poor engagement of the protrusions 104 into the slot 148. This problem becomes especially serious in cases when the connectors are used in locations where the worker cannot see them directly.
In addition, in cases when the plug housing and the cover housing enveloping it are molded as a single unit, the sealing elements located on the plug housing can not be molded in two colors. It is also difficult to implement a so-called double-lock device providing a secondary securing of the contacts when the insertion is carried out in the direction perpendicular to the direction of contacts. In this case, it is also impossible to effectively increase the contact-retaining force.